The present invention generally relates to metal-oxide-semiconductor field-effect transistors (MOSFET), and more specifically, to nanosheet gate all around devices.
The MOSFET is a transistor used for amplifying or switching electronic signals. The MOSFET has a source, a drain, and a metal oxide gate electrode. The metal gate is electrically insulated from the main semiconductor n-channel or p-channel by a thin layer of insulating material, for example, silicon dioxide or glass, which makes the input resistance of the MOSFET relatively high. The gate voltage controls whether the path from drain to source is an open circuit (“off”) or a resistive path (“on”).
N-type field effect transistors (nFET) and p-type field effect transistors (pFET) are two types of complementary MOSFETs. The nFET uses electrons as the current carriers and with n-doped source and drain junctions. The pFET uses holes as the current carriers and with p-doped source and drain junctions.
Nanosheet devices are FET devices that have a relatively thin and substantially planar channel region formed from a semiconductor material. The channel region is surrounded on all sides by a metal gate to form a gate all around device.